Engine starter drives



April 18, 1961 G. s. SPENCER ENGINE STARTER DRIVES Filed Dec. 16, 1959 INVENTOR.

ATTORNEY WITNESS:

ENGINE STARTER DRIVES Glenn S. Spencer, Horseheads, N.Y., assignor to The Bendix Corporation, a corporation of Delaware Filed Dec. 16, 195 9, Ser. No. 859,999 8 Claims. (Cl. 74-7) The present invention relates to engine starter drives and more particularly relates to an improved arrangement for securing the drive assembly to the starting motor armature shaft.

A drive assembly is generally a sub-assembly adapted to be mounted on an extension of the starter motor armature shaft. Until now drive assemblies, similar to the illustrated rubber folo-thru type, have been secured to the starting motor armature shafts by means of pins passing through the sleeve at a point under the threaded screw shaft. This securing arrangement has proven to be somewhat undesirable. In order to mount the drive on the armature shaft the screw shaft must be provided with a hole to permit the insertion of the pin in the armature and sleeve mounting holes. To align three holes in order to secure the drive to the armature shaft is, of course, a time consuming operation for an assembler.

The pin now used, in an effort to eliminate pin drift,

. is What is referred to as a roll pin. This type of pin expands Within the aligned mounting holes but is expensive to manufacture. Radial drift of a solid pin would be detrimental since any displacement wouldinterfere with the relative rotation between the sleeve and the surrounding screw shaft.

A further disadvantage of the present mounting means can result from a chip or shavings on the pin becoming lodged between the sleeve and shaft, or between the screw shaft and control nut, thus causing excessive wear and detrimentally affecting the desired operation of the starter drive.

. It'is an object of the present invention to provide a novel drive assembly which is securable to a starting motor armature shaft in an efiicient and reliable manner and which is simple and economical inconstruction.

It is another object to provide a more convenient and time saving means for mounting the drive assembly on a starting motor armature shaft. i

, It is still another object to provide a drive assembly which is securable to a driving motor through the uses of a less expensive solid pin so positioned as not to interfere with relative rotating parts if a small amount of pin drift should occur.

It is a further object to provide drive assembly SECUI'? ing means which will considerably reduce the possibility Ofintroducing detrimental foreign matter between adjacent rotatingparts.

2 extending into the flange openings and engaging the securing pin;

Fig. 4 is a fragmentary longitudinal sectional view illustrating a second embodiment of the invention in a presecured position; and i Fig. 5 is a fragmentary view of the embodiment disclosed in, Fig. 4 illustrating the denticle axially extending into the flange opening to engage the securing pin whereby the starter drive assembly is fixedly mounted on the starting motor armature shaft.

In Fig. l of the drawing there is illustrated an armature shaft 11 of a starter'motor (not shown). A sleeve 12 is adapted to be fixedly mounted on the shaft 11 by means to be hereinafter described and slidably journalled thereon is a screw shaft 13. A pinion 14 is journalled on the reduced extremityof the shaft 11 for movement into and out of mesh with a gear 16 of the engine to be started.

A clutch member 17 is slidably but non-rotatably secured to the sleeve 12 by means of axial splines 18. The clutch member 17 is provided with teeth members 19 engageable with like teeth 21 on the screw shaft. The teeth are so formed as to provide an overrunning clutch connection between the clutch member 17 and the screw shaft 13 operable when the screw shaft is driven by the engine at speeds exceeding the speed of the starting motor.

A stop member 22 is secured to one extremity of the sleeve 12 adjacent the end of the screw shaft 13 and is held thereon by means of a snap ring 23. A thrust washer 24 is interposed between the end of the screw shaft and the stop member. A spring washer 26 is inter calated between the thrust washer and the stop member to cause the teeth 19, 21 of the clutch member 17 and screw shaft 13, respectively, to normally maintain engagement. 7 I

A control nut 27 is threadedly mounted on the screw shaft and has portions extendingradially into engagement with slots 28 in the barrel housing 29. The pinion 14 is drivingly connected to the barrel by a spline-like connection, as at 31, and has a radial flange 3-2 secured on its inner extremity by any convenient method locating within the barrel housing. A mesh enforcing spring 33 is con tained within the. barrel housing and yieldinglyf abuts against the control nut 27 and the pinion flange 32 to insure meshing in the event of an end-to-end abutment between teeth of the pinion 14 and the engine gear 16.

Latch means comprising a centrifugally actuated detent and a notch means is provided to maintain pinion mesh and provide the folo-thru" characteristics. The detent member 34 is housed within the control nut 27 and yieldingly engages the threaded portion of the screw shaft Further objects and advantages will be apparent from the following description taken in connection with the accompanying drawing, in which:

1 ,Fig'. i is a longitudinal sectional view, partly broken l -,3 ;is 'a,long'itudinal sectional view ofFig. .2 taken. on' the' plane of line 3-3, illustrating the denticles axially 13. When the pinion is fully or partially meshed with the gear of the engine the detent 34 will radially engage a notch or recess 36 formed in the screw shaft 13 thereby insuring continuing pinion mesh until the engine is reliably started yet allowing sufiicient axial movement of the screw shaft to enable the clutch teeth to overrun. After the engine has started and drivingly rotates the pinion at or above a predetermined rotational speed centrifugal force will cause the detent 34' to be withdrawn from the recess 36 and allow the control nut to traverse the screw shaftin a deme'sh direction, thus causing the pinion to demesh. j

During initial application of torque to the engine gear, screw-jack action between the control-nut and screw shaft will axially force the clutch member 17 in a demeshing direction. This screw-jack action will; within limits, be absorbed by an'elastically deformab1e-compression ring element 37.. The element 37 preferably made of rubber is compressively confined between athrust or pressure plate 38, mounted on the clutch 17 and .a'sec- 0nd thrust or pressure plate mounted on an increased diameter portion 40 of the sleeve 12. The thrust plate 38 abuts a flange 39 formed on the clutch member and the second thrust plate 41 journalled on the sleeve portion 40 abuts the shoulder 48 provided by the flange 47 on the sleeve member 12. The compressive element and portions of the thrust plates are housed within a shell 42. The shell extremities are inturned as at 43 and 44 with the thrust plate 41 being axially secured to the shell 42 as illustrated at 46. v

The flange 47 has formed therein a pair of aligned radial apertures or slots 49 opening radially outwardly to the peripheral portion of the flange and axially outward to the side of the flange providing the abutting shoulder 48. a

The shaft is provided with the transverse passage 51 extending diametrically therethrough, v

The thrust plate 41 is provided with a pair of diametrically opposite detents or denticles 52 formed therein which extend axially towards the shoulder 48. The rubber compression element 37 due to its compressive confinement within the shell housing 42 urges the thrust plate 41 in the axial direction towards the flange 47 causing the denticles 52 to compressively but yieldably abut the flange shoulder 48 immediately adjacent the slot openings 49 as best illustrated in Fig. 1.

After the drive asembly is slipped on to the armature shaft 11 it is non-rotatably and axially aflixed to the shaft. This is accomplished by inserting securing means such as a solid pin 53 in the shaft passage 51 with the pin extremities engaging portions of the aligned flange slots 49. The thrust plate 41 is then rotated relative to the sleeve 12 on the sleeve portion 40 and upon suflicient rotation the denticles 52 will be caused to snap into the slots 49 of the flange 47 to engage the extremities of the pin 53 as best illustrated in Figures 2 and 3.

The denticles 52 should have suflicient axial length to provide adequate clearance between the pin 53 and the shell inturned extremity 44 when the pin 53 is inserted in the aligned flanged slots 49 and shaft passage 51. It will be noted further that the compression of the element '37 due to the compressive engagement of the denticles 52 against the flange shoulder 48 is more easily attained by having sliding engagement between the thrust plate 1 38 and the shell housing 42 and, of course, is necessary for proper clutch operation.

In Figs. 4 and 5 there is illustrated a second embodiment of the invention wherein the sleeve 12 is provided with a flange 47' on one end thereof. The flange is provided with a pair of radially aligned slots 56 and 57. The slot 56 provides a radial passage opening to the peripheral portion and to one side 48' of the flange 47'. The flange slot 57, however, extends radially outward a limited amount but does not open to either the side or top portions of the flange 47. The shaft 11 is also pro-' vided with a transverse passage 51'. t

A thrust plate 58 is contained in a shell housing 42' in a manner previously described. The thrust plate 58 is provided with a single detent or denticle 59 compressively abutting the flange shoulder 48' adjacent the axial opening of passage 56. The compressive force exerted on the thrust plate 58 and denticle 59 against the shoulder 48 is supplied by the compression element 37' (Fig. 4).

The sleeve 12 is slipped on the shaft 11' with the flange slots 56 and 57 registering with the shaft passage 51. Since the slot 57 does not extend outwardly beyond the flange there with be provided, when the slots and passage are in registry, a blind hole into which a securing member; such as a solid pin 53', can be inserted; It will be apparent then that when the pin is inserted in the shaft passage 51, it will have its extremities engaging portions of the slot 56 and all of slot-57.

The useof blind hole arrangement has th'e added ad vantage that the pin is automatically centered and lo- 'cated upon insertion in the slots 'and passage and does not require the immediate engagement between the denticle and pin to maintain proper pin location.

The thrust plate 58 is rotatably mounted on increased diameter portion 40' on the sleeve 12' adjacent the shoulder 48 and upon rotation the denticle 59 will be caused to snap into a portion of the flange slot 56 and to axially extend over a portion of the pin 53' in a manner best illustrated in Fig. 5.

T he thrust plate denticle 59 does not require as great an amount of axial length as the denticles 52 in the first embodiment illustrated in Figs. l-3, inclusive. The single denticle 59 has the added advantage of appreciably tilting the thrust plate 58 yet providing sufficient clearance to allow the pin 53' to be freely inserted in the aligned slots and passage free from obstruction by the inturned portion 44 of the shell 42'. The clearance obtainable is best illustrated in Fig. 4 showing the pin partially inserted in the slot 56 and passage 51'.

In the manufacture of the drive assembly as a 's'ubassembly the thrust plate and denticles will be positioned in their compressive engagements against the shoulders 48 and 48' of the sleeve flanges (Figs. 1 and 4). The compressive force extended by the compression element 37 will be suflicient to maintain the thrust plate and denticles in this position during shipment and storage. When the sub-assembly is mounted on the armature shaft the compression element and the thrust plates having the denticles formed thereon can be rotated with relative case after the pin has been inserted into the aligned shaft passage and flange slots.

It can be appreciated that the device herein described for mounting a starter drive sub-assembly on a starter motor armature shaft provides a simple and efficient means for non-rotatably securing the sleeve and associated components on the shaft with the denticle or denticles, as the case may be, effectively eliminating any radial displacement of the securing pin. It can be further appreciated that in the event repairs must be made the disassembly of the drive assembly from the armature shaft can be accomplished with comparable ease.

I claim:

1. In a -starter drive, a power shaft having a trans verse passage extending diametrically therethrough, a sleeve journalled on the shaft having aligned apertures formed in one end thereof adapted to register with the shaft passage, a pinion journalled on the shaft for movement into and out of mesh with a gear of an engine to be started, means transmitting actuation from the sleeve to the pinion, resilient yielding means including a slidable and rotatable thrust plate mounted on the sleeve for resisting axial movement of the actuation transmitting means in the demeshing direction, means inserted in the shaft passage and registering sleeve apertures for rotatably and axially securing the sleeve to the shaft, and retaining means on the thrust plate preventing the radial displacement of said securing means from the passages and apertures; wherein said sleeve includes an annular flange formed thereon providing shoulder means adjacent said thrust plate, said flange containing portions of said aligned apertures, one of said' apertures opening radially outward to the flange peripheral area and opening axially to said shoulders, said registering apertures and shaft passage being positioned to forma radial blind passage in the drive to receive said securing means,'said thrust plate normally yieldingly abutting the flange shoulder, and said retaining means comprising a dctent axially extending from the thrust plate yieldably abutting the 'flange shoulder prior to insertion of said securing means into said blind passage and upon rotation of the thrust plate to its normal flange abutting position extending .into the radial and axial openingof said blind passage to engage portions of said securing means.

2. In a starter drive,'a power shaft'havin'g a'transveise passage extending diametrically therethrough, a sleeve journalled on the shaft having aligned apert'ures formed in one end thereof adapted to register with the shaft passage, a pinion journalled on the shaft for movement into and out of mesh with a gear of an engine to be started, means transmitting actuation from the sleeve to the pinion, resilient yielding means including a slidable and rotatable thrust plate mounted on the sleeve for resisting axial movement of the actuation transmitting means in the demeshing direction, means inserted in the shaft passage and registering sleeve apertures for rotatably and axially securing the sleeve to the shaft, and retaining means on the thrust plate preventing the radial displacement of said securing means from the passages and apertures; wherein said sleeve includes an annular flange formed thereon providing shoulder means adjacent said thrust plate, said flange containing portions of said aligned apertures, said apertures opening radially outward to the flange peripheral area and opening axially to said shoulder, said registering apertures and shaft passage being positioned to provide a transverse passage through the drive to receive said securing means, said thrust plate normally yieldingly abutting the flange shoulder, and said retaining means comprising a pair of denticles axially extending from the thrust plate yieldably abutting the flange shoulder prior to insertion of said securing means into said transverse passage and upon rotation of the thrust plate to its normal flange abutting position extending into the radial and axial openings to engage portions of said securing means.

3. A starter drive as set forth in claim 1 wherein the securing means comprises a pin member seated in said blind passage and having an end portion engageable with said detent.

4. A starter drive as set forth in claim 2 wherein the securing means comprises a pin member mounted in the transverse passage and having its end portions engageable with said denticles.

5. In a starter drive a rotating power shaft having a transverse passage extending therethrough, a sleeve adapted to be fixedly mounted on the shaft and including an apertured flange formed on one end thereof, said flange apertures adapted to register with the shaft passage, a screw shaft rotatably and slidably journalled on the sleeve, a pinion journalled on the shaft for movement into and out of mesh with a gear to the engine to be started, means for actuating the screw shaft from the sleeve including a clutch memberv having a connection with the screw shaft, means actuating the pinion from the screw shaft, yielding means resisting axial movement of said clutch member in the demeshing direction fixedly mounted on the shaft, detent means on the pressure plate yieldably abutting portions of the sleeve flange adjacent said apertures to dispose the pressure plate axially clear of said flange apertures and adapted upon rotation of said pressure plate to axially extend above the pin extremities to serve as abutments whereby the pin is confined in said passage. 7

6. In a starter drive a sub-assembly unit comprising a sleeve having a flange with aperture means formed therein said sleeve adapted to be mounted on a starting motor shaft, pinion means adapted to be journalled on the starting motor shaft for movement into and out of mesh with a gear of an engine to be started, means including a clutch member for transmitting actuation from the sleeve to the pinion, yielding means resisting axial movement of said clutch member in the demeshing direction, said yielding means including an elastic compression element oompressively engaging a rotatable and slidable thrust plate mounted on the sleeve, detent means on the thrust plate yieldably abutting said flange at a point adjacent said aperture means to dispose the thrust plate axially clear of said aperture means, said thrust plate being rotatably shiftable against the compressive force of the compression element to cause the thrust plate to flatwise engage said flange with the detent means axially extending into a portion of said aperture means.

7. A starter drive as set forth in claim 6 wherein the sleeve flange aperture means includes diametrically oppo site slot means formed therein one of said slot means forming a transverse radial passage having an opening in one side and the peripheral portion of the flange, the other of said slot means forming a blind outwardly extending radial passage; the detent means comprising an axially extending denticle formedon the thrust plate.

8. A starter drive as set forth in claim 6 wherein the sleeve flange aperture means includes diametrically opposite slot means formed therein said slots forming transverse radial passages having openings to one side and the peripheral portion of said flange, the detent means comprising axially extending denticles oppositely disposed on the thrust plate.

References Cited in the file of this patent UNITED STATES PATENTS 

